Effects of Anion Identity and Concentration on Electrochemical Reduction of CO2
Resasco, J., Lum, Y., Clark, E., Zeledon, J., Bell, A. T. Effects of anion identity and concentration on electrochemical reduction of CO2. ChemElectroChem, DOI: 10.1002/celc.201701316 (2018).
Hydrogen-containing anions (HSO4-, HCO3-, HBO3-, H2PO4-) buffer the electrolyte against the effects of concentration polarization (e.g., a rise in cathode pH) and provide a source of H atoms for CO2 reduction via reactions such as HCO3- + e- → H* + CO3^2-.
Significance & impact
By choice of electrolyte anions with a high pKa, product selectivity can be shifted from H2 and CH4 to C2 products.
An investigation was conducted of the effects of bicarbonate buffer concentration and the composition of other buffering anions on the partial currents of the major products formed by reduction of CO2 over Cu.Discrete (Ni-La-Co-Ce)Ox coatings were synthesized on a uniform BiVO4 thin film yielding 858 catalyst/BiVO4 assemblies with 3 different catalyst loadings.